Red light induced folding of single polymer chains.

We pioneer the photochemical generation of single chain nanoparticles (SCNPs) at the to-date mildest reported wavelength of 625 nm by exploiting the photochemical uncaging of methylene blue protected amines. The protected amines are tethered to polymers prepared via reversible addition-fragmentation chain transfer (RAFT) polymerisation, and subsequently undergo intrachain crosslinking by amide formation.